The present invention relates to a method and a device for practicing aquaculture in the open sea.
In countries with well-sheltered bays, e.g. deep fjords, one or more enclosures consisting of a net or a netting lying under water are arranged on the surface, and inside are placed recently hatched fishes (e.g. sea or salmon trout) which are fed with the prepared food from a boat. Such enclosures, nets or nettings as presently known in the art form flexible deformable assemblies that are very difficult to handle.
This form of aquaculture cannot be practiced along an inadequately sheltered coastline, as is particularly the case along the coasts of France, because the waves and storms would exhaust the fishes which cannot endure such disturbances without harmful effects and would also deform and end up destroying the enclosures containing the fishes which are in the process of being bred.
Therefore, in the prior art the use of completely sealed enclosures has been suggested which are weighted in such a way that they sink in the water and rest on the bottom of the sea. Unfortunately, it has been found that even on the sea bottom, at a depth propitious to breeding, that is to say, between 0 and 30 meters, said enclosures are not secure from the motions of the water caused by violent storms or by deep sea currents, so that they scrape against the sea bottom and deteriorate and tear, allowing the fishes to escape. Furthermore, it is necessary to lift the enclosures at regular intervals so as to assure proper nourishment of the fishes or to remove algae and other marine growths. This calls for intervention from the boats, which must be equipped with complicated and costly hoisting gear.